Polyurea coated trailer

ABSTRACT

The present invention relates to polyurea composition coated trailers and methods of making the same. In an embodiment, the present invention is directed to a trailer comprising a frame having a front side and a back side, at least one axle coupled to the frame, a plurality of wheels coupled to the at least one axle, and a polyurea coating, wherein the polyurea coating encapsulates at least a portion of the frame. In an embodiment, the present invention is directed to a method for protecting a metal trailer from corrosion comprising cleaning the surfaces of a metal trailer and applying a layer of a polyurea composition to the surfaces of the metal trailer.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 11/543,407,filed Oct. 4, 2006, which is a divisional of application Ser. No.11/039,073, filed Jan. 20, 2005, now U.S. Pat. No. 7,125,032, whichclaims priority from provisional application Ser. No. 60/560,339, filedApr. 6, 2004, which applications are incorporated herein by reference intheir entirety.

FIELD OF THE INVENTION

The present invention relates to trailers. In particular, the presentinvention relates to trailers that are coated with a protective layer.

BACKGROUND OF THE INVENTION

Trailers have utility for transporting various materials and objects.For example, boats and other watercraft can be transported on trailers.The structural elements of a trailer can be made of many differentmaterials. Frequently, trailers are made of steel components. Steel isstrong and relatively cost efficient. However, steel is subject todamage from corrosion.

To protect against corrosion, trailers frequently are provided with aprotective coating. For example, a coating of paint may be applied toprotect a trailer made of steel from corrosion. The coating of paintprevents moisture from reaching the surface of the metal where is maycause corrosion. The coating of paint may also protect the steel fromcompounds that may enhance corrosion such as road salt and the like.

However, protective finishes can be breached, leaving parts of thetrailer unprotected. For example, as trailers are pulled over roadways,the surfaces of may be hit with roadway debris. Small stones may bekicked up by the tires and chip off pieces of the protective finish.Other sorts of roadway debris may also come in contact with theprotective finish and damage it. In addition, the protective finish maybe breached through physical contact of the boat trailer with otherobjects. For example, other objects may contact the trailer when a boatis loaded or unloaded from the trailer.

Protective finishes on trailers also serve an aesthetic purpose. Thefinishes may be colored to match the intended cargo, such as theparticular boat, or may be colored in accord with the logo of themanufacturer. Accordingly, breaches of the protective finish may makethe appearance less aesthetic and therefore diminish the value of thetrailer.

While common automotive paint is a typical material used for aprotective finish, other finish materials are used. For example,polyurethane compositions are known for use as a protective finish.However, polyurethane compositions are susceptible to damage fromUV-light exposure. This can be an issue with boat trailers as they arefrequently parked in full exposure to sunlight. Moreover, polyurethanecompositions can lose their flexible and protective properties attemperature extremes. Therefore, a protective finish made from apolyurethane composition will be more susceptible to failure at, forexample, very low temperatures.

Polyurethane systems also typically utilize a catalyst to promote propercuring. Use of catalysts in curing processes can make application moredifficult as the process is usually temperature and moisture sensitive.Additionally, the catalyst may become a deteriorating element in somepolyurethane systems.

Therefore, a need exists for a trailer that is protected from damage andprovides a lasting aesthetic appearance.

SUMMARY OF THE INVENTION

One inventive aspect of the present disclosure relates to polyureacomposition coated trailers and methods of making the same. Anotherinventive aspect is directed to a trailer comprising a frame having afront side and a back side, at least one axle coupled to the frame, aplurality of wheels coupled to the at least one axle, and a polyureacoating, wherein the polyurea coating encapsulates at least a portion ofthe frame. A further inventive aspect is directed to a method forprotecting a metal trailer from corrosion comprising cleaning thesurfaces of a metal trailer and applying a layer of a polyureacomposition to the surfaces of the metal trailer.

Examples of a variety of aspects in addition to those described aboveare set forth in the description that follows. It is to be understoodthat the forgoing summary and the following detailed description areexemplary and explanatory only and are not restrictive of the broadinventive aspects that underlie the examples disclosed herein.

DRAWINGS

The invention may be more completely understood in connection with thefollowing drawings, in which:

FIG. 1 shows a typical polyurea reaction.

FIG. 2 is a perspective view of a trailer coated in accordance with anembodiment of the invention.

FIG. 3 is a perspective view of a trailer frame as it would appear justafter the coating process in an embodiment of the invention.

FIG. 4 is a perspective view of a trailer with a torsion axle inaccordance with an embodiment of the invention.

FIG. 5 is perspective view of the trailer of FIG. 4 with some componentsremoved.

FIG. 6 is a cross-sectional view of the trailer frame of FIG. 3 takenalong line A-A′.

FIG. 7 is a cross-sectional view of an alternative embodiment of thetrailer frame of FIG. 3 taken along line A-A′.

FIG. 8 is a cross-sectional view of a trailer frame taken along lineA-A′ of FIG. 3, in an embodiment showing a paint layer disposed on apolyurea layer.

While the invention is susceptible to various modifications andalternative forms, specifics thereof have been shown by way of exampleand drawings, and will be described in detail. It should be understood,however, that the invention is not limited to the particular embodimentsdescribed. On the contrary, the intention is to cover modifications,equivalents, and alternatives falling within the spirit and scope of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

In an embodiment, the present invention is directed to a trailercomprising a frame having a front side and a back side, at least oneaxle coupled to the frame, a plurality of wheels coupled to the at leastone axle, and a polyurea coating, wherein the polyurea coating covers atleast a portion of the frame. The polyurea coating may also fullyencapsulate portions of the frame. In an embodiment, the presentinvention is directed to a method for protecting a metal trailer fromcorrosion comprising cleaning the surfaces of a metal trailer andapplying a coating of a polyurea composition to the surfaces of themetal trailer. Various components of the invention will now be describedin greater detail.

Coating Compositions:

Compositions of an embodiment of the present invention comprise apolyurea composition. A polyurea is generated from the reaction of adiisocyanate or polyisocyanate with a compound containing amine groups.A prototypical polyurea formation reaction is shown in FIG. 1.Accordingly, polyurea systems comprise at least two components. Thefirst component comprises an isocynate and the second component is acomponent that contains a reactive amine group. As referred to herein,the term polyurea composition refers to a composition containingpolyurea-type chemical bonding and excludes polyurethane-type chemicalbonding. Thus, the term “polyurea composition” does not includepolyurea/polyurethane blends.

The first component may be an aliphatic diisocyanate, such as1,4-diisocyanatobutane, 1,6-diisocyanatohexane (HDI),1,12-diisocyanatododecane, 2-methyl-1,5-diisocyanatopentane, or analiphatic polyisocyanate. The first component may also be acycloaliphatic diisocyanate such asmethylenedicyclohexylene-4,4′-diisocyanate,3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophoronediisocyanate, IPDI), 2,2,4-trimethylhexyl diisocyanate, orcyclohexylene-1,4-diisocyanate. The first component may be anaromatic-aliphatic diisocyanate such as m-xylylene diisocyanate ortetramethyl-m-xylylene diisocyanate. The first component may also be anaromatic diisocyanate, such as 2,6-toluene diisocyanate (TDI), 1,3- and1,4-bis(2-isocyanatoprop-2-yl) benzene (TMXDI), 2,5-toluenediisocyanate, 2,4-toluene diisocyanate, m-phenylene diisocyanate,p-phenylene diisocyanate, methylene bis(o-chlorophenyl diisocyanate),methylenediphenylene 4,4′-diisocyanate, polycarbodiimide-modifiedmethylenediphenylene diisocyanate,(4,4′-diisocyanato-3,3′,5,5′-tetraethyl) diphenylmethane,4,4′-diisocyanato-3,3′-dimethoxybiphenyl (o-dianisidine diisocyanate),5-chloro-2,4-toluene diisocyanate, or 1-chloromethyl-2,4-diisocyanatobenzene. The first component may also comprise mixtures of differentisocyanates. One of skill in the art will appreciate that many differentdi- or poly-isocyanates could be used depending on the particularapplication.

The second component can be an aliphatic or aromatic amine resin.Suitable polyamines include ethylene diamine, 1,2- and1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, isophoronediamine, isomer mixture of 2,2,4- and 2,4,4-trimethyl hexamethylenediamine, 2-methyl pentamethylene diamine, diethylene triamine, 1,3- and1,4-xylene diamine, a, a, a′, a′-tetramethyl-1,3- and -1,4-xylylenediamine and 4,4-diaminodicyclohexyl methane. Other compounds to beconsidered as suitable diamines include hydrazine, hydrazine hydrate andsubstituted hydrazines, such as N-methyl hydrazine, N,N′-dimethylhydrazine and homologues thereof, as well as acid dihydrazides, adipicacid, β-methyl adipic acid, sebacic acid, hydracrylic acid andterephthalic acid, semicarbazidoalkylene hydrazides, such asβ-semicarbatidopropanoic acid hydrazide, semicarbazidoalkylene carbazineesters, such as 2-semicarbazidoethyl carbazine ester oraminosemicarbazide compounds, such as β-aminoethylsemi-carbazidocarbonate. One of skill in the art will appreciate thatmany different di- or poly-amines could be used depending on theparticular application.

Polyurea systems may also include other components to modify theproperties of the end product. By way of example, polyurea systems mayalso comprise nonreactive additives such as fillers, pigments,stabilizers, plasticizers, organic tackifiers, antioxidants,compatibilizers and the like.

Polyurea systems generally do not use a catalyst to speed up the curingprocess. The two components cure very rapidly after they are combined,for example, in as few as 5-15 seconds. The product resulting from thereaction is generally inert. However, the properties of the resultingpolyurea composition will vary as a function of isocyanate-to-amineratio, polyisocyanate and polyamine architecture, order of reactantaddition, mixing speed, temperature, applicator throughput, applicatorconfiguration and size, residence time, residence time distribution, andwhether any fillers, additives, or property modifiers are added to thecomposition. One of skill in the art will appreciate that the propertiesof the resulting polyurea composition can be modified as desired throughchanges to these variables.

Polyurea coating systems are available commercially from a variety ofsources. One such system is TURBOLINER® 117502, available fromTurboliner Inc., 1 West Cameron Avenue, Kellogg, ID 83837.

Coated Components:

In an embodiment of the invention, metal components of a trailer arefully encapsulated with the polyurea coating of the invention. In otherembodiments, at least a portion of the trailer is coated with a polyureacomposition. In some embodiments, the trailer is a boat trailer.Referring now to FIG. 2, a completed boat trailer 10 is shown inaccordance with an embodiment of the invention. The boat trailer 10 hasa frame that comprises side rails 18 connected together toward the frontby a transverse hitch bar support member 20 and the hitch bar 14. In anembodiment of the invention, the side rails 18 are encapsulated by apolyurea coating. In an embodiment of the invention, the transversehitch bar support member 20 and/or the hitch bar 14 are encapsulated bya polyurea coating. Toward the middle, the side rails 18 are connectedby transverse frame members 32 and 34; and at the aft the side rails 18are connected by aft transverse frame members 36 and 38. In anembodiment of the invention, the transverse frame members 32 and 34, andthe aft transverse frame members 36 and 38 are encapsulated by apolyurea coating. At the front of the hitch bar 14, a hitch coupling 12is attached. A winch stand 24 is attached to the hitch bar 14 andsupports the placement of a winch 26. In an embodiment of the invention,the winch stand 24 is encapsulated by a polyurea coating. A winch cableguide 28 is mounted just in back of the winch 26. A trailer jack 16 isshown mounted on a side rail 18, however, it may be mounted onto othercomponents as a simple matter of design choice. A step member 30, mayalso be mounted on a side rail 18 for the convenience of the traileruser. In an embodiment of the invention, the step member is encapsulatedby a polyurea coating. In the trailer shown in FIG. 2, there is a frontaxle 40 and a rear axle 42. In an embodiment of the invention, the frontaxle 40 and/or the rear axle 42 are encapsulated by a polyurea coating.However, one of skill in the art will understand the invention disclosedherein is not limited to double-axle trailers. A keel roller 44 ismounted on aft transverse frame member 36 and helps the functions of thetrailer when boats are loaded and unloaded. In the trailer shown in FIG.2, there are four wheels 66 and a spare wheel 22. The wheels arepartially covered by the right wheel fender 46 and the left wheel fender48. The front axle 40 is attached to the frame through a left front axlespring 52 and a right front axle spring 70. Similarly, the rear axle 42is attached to the frame through a left rear axle spring 50 and a rightrear axle spring 68. FIG. 4 shows an embodiment of the invention 140with a torsion type axle system. This embodiment has a front torsionaxle 144 and a rear torsion axle 142.

The trailer has a pair of rear brake lights 54, 56. The trailer also haselements designed to support the boat on the trailer. In the embodimentshown in FIG. 2, the trailer has a pair of inner hull skids 58, 64 and apair of outer hull skids 60, 62. However, one of skill in the art willappreciate that many other elements may be used to support the boat onthe trailer including roller systems and the like. Therefore, any sortof structure used for cradling a boat may be coated with a polyureacomposition in accordance with the invention.

In FIG. 5, an embodiment of the invention with a torsion type axlesystem is shown 150 with various components removed. In this figure, aplurality of step member supports 152 are shown which underlie the stepmember 30. In an embodiment of the invention, the step member supports152 are coated with a polyurea composition. A plurality of skid supports156 are attached to components of the frame including transverse framemembers 32 and 34 and aft transverse frame members 36 and 38. In anembodiment of the invention, the skid supports 156 are coated with apolyurea composition. A plurality of fender support members 154 areattached to the side rails 18. In an embodiment of the invention, thefender support members 154 are coated with a polyurea composition.

While the invention has been described above in the context of a boattrailer, one of skill in the art will appreciate that many types oftrailers could be similarly coated with a polyurea composition withoutdeviating from the spirit of the invention. Also, while many componentsof the trailer are described as being encapsulated, these samecomponents may also be at least partially coated. As used herein, theterm “encapsulated” means to be fully surrounded when viewed incross-section at a particular angle through the particular component.

Mode of Application:

Polyurea compositions have a high curing speed and a very short mixingtime. Accordingly, in some embodiments, the polyurea composition isapplied in a manner to account for the high curing speed. In anembodiment, high pressure is used in an application device to properlymix the components. High temperature may also be used to lower theviscosity of the components to ensure optimal mixing. The applicationdevice may comprise a proportioning pump and a spray gun. Such devicesmay be referred to as plural component proportioning systems and areavailable from many commercial suppliers. By way of example, one spraygun that may be used is the LS GUN®, made by Glasscraft, available fromTurboliner Inc., 1 West Cameron Avenue, Kellogg, ID 83837. The LS GUN®has an orifice of 0.013 inches.

In an embodiment, the surfaces of the boat trailer to be coated arefirst prepared. Various mechanical and chemical means may be used toprepare a metal surface for subsequent coating. By way of example, thesurface of the boat trailer to be coated may be prepared by sand blastedprovide a clean surface free of oil. However, one of skill in the artwill appreciate that there are many ways of preparing a metal surfacebefore application of a coating.

Before coating the trailer with a polyurea composition, those componentsthat are not to be coated are removed (or are not yet added). FIG. 3shows a trailer 72 that has just been coated in accordance with anembodiment of the invention.

After the metal surfaces have been prepared and those components thatare not to be coated are removed, the polyurea composition of theinvention is applied. In some embodiments this is conducted with aplural component proportioning system and the composition is sprayedonto the metal surfaces of the trailer frame.

A polyurea coating that is too thin may not be as durable. In someembodiments, the polyurea composition is applied in a layer that isgreater than or equal to 0.015 inches thick. A polyurea coating that istoo thick may not be economical. In some embodiments, the polyureacomposition is applied in a layer that is less than or equal to 0.035inches thick. In an embodiment, the polyurea composition may be appliedin a layer from 0.015 inches to 0.035 inches thick. In a particularembodiment, the polyurea composition may be applied in a layer that is0.025 inches thick.

The way in which the polyurea coating is applied can allow it toencapsulate various components. By way of example, spraying the polyureacomposition onto the metal surfaces of the trailer frame can allow thepolyurea coating to encapsulate the frame components. Referring now toFIG. 6, a cross-sectional view of a trailer frame taken along line A-A′of FIG. 3 is shown. The coated frame 100 comprises a rectangular metalbar 104 that defines a metal bar lumen 106. The polyurea coating 102encapsulates the rectangular metal bar 104 such that there aresubstantially no exterior surfaces of the rectangular metal bar 104 thatare not coated with the polyurea composition. However, one of skill inthe art is aware that metal bar stock used for making structuralelements can come in a variety of different shapes and configurations.Referring now to FIG. 7 a cross-sectional view of an alternativeembodiment of the trailer frame taken along line A-A′ of FIG. 3 isshown. In FIG. 7, the coated frame 110 comprises a C-shaped metal bar116 that partially defines a C-shaped metal bar lumen 118. The polyureacoating has an interior coating 114 and an exterior coating 112, suchthat the C-shaped metal bar 116 is encapsulated by the polyurea coating.

Paint Coatings

The inventors of the present application have surprisingly found thatthe chip-resistance of paint itself is improved when it is applied overa polyurea coating when compared with paint that is applied directlyonto a metal substrate. While not intending to be bound by theory, it isbelieved that some of the mechanical forces from impact are absorbed bythe polyurea coating resulting in less energy being absorbed by thepaint coating leading to reduced fracturing of the paint surface.

In an embodiment, the invention comprises a boat trailer coated with apolyurea composition as described above along with a paint coatingdisposed over the polyurea coating. In an embodiment, the paintcomprises a polyurethane component. An example of a suitable paintincludes AUE-200 available from PPG paints, at least through theirdistributor R and E Automotive Paint and Supply, 57 Avalon Lane,Mountain Home, AR 72653. The layer of paint may be about 0.0015 to0.0020 inches thick.

Referring now to FIG. 8, a cross-sectional view of a trailer frame takenalong line A-A′ of FIG. 3 is shown in an embodiment showing a paintlayer disposed on a polyurea layer. The coated frame 130 comprises arectangular metal bar 104 that defines a metal bar lumen 106. Thepolyurea coating 102 encapsulates the rectangular metal bar 104 suchthat there are substantially no exterior surfaces of the rectangularmetal bar 104 that are not coated with the polyurea composition. Thepaint coating 132 is disposed on the polyurea coating 102.

It will be appreciated that, although the implementation of theinvention described above is directed to a boat trailer, the presentinvention may be used with other types of trailers, and is not limitedto boat trailers. In addition, while the present invention has beendescribed with reference to particular implementations, those skilled inthe art will recognize that many changes may be made hereto withoutdeparting from the spirit and scope of the present invention.

1. A boat trailer comprising: a frame having a front end and a back end,the frame including first and second spaced-apart side rails havinglengths that extend between the front and back ends of the frame, thefirst and second side rails having portions that diverge from oneanother as the portions of the first and second side rails extend fromthe front end toward the back end of the frame, the frame also includinga plurality of transverse frame members that extend across a width ofthe frame between the first and second side rails; a boat hull supportstructure coupled to the frame; at least one axle coupled to the frame;a plurality of wheels coupled to the at least one axle; a winch standcoupled to the frame; and a coating that encapsulates at least portionsof the first and second side rails, the transverse frame members, theaxle, and the winch stand, the coating including at least isocyanate anda reactive amine.
 2. The boat trailer of claim 1, wherein the reactiveamine includes an aliphatic or an aromatic amine resin.
 3. The boattrailer of claim 1, wherein the coating comprises a polyureacomposition.
 4. The boat trailer of claim 1, further comprising stepmember supports on which a step is supported, the step member supportsprojecting outwardly from at least one of the first and second siderails, and the step member supports being coated by the coating.
 5. Theboat trailer of claim 1, further comprising fender supports on whichfenders are supported, the fender supports projecting outwardly from thefirst and second side rails, and the fender supports being coated by thecoating.
 6. The boat trailer of claim 3, further comprising step membersupports on which a step is supported, the step member supportsprojecting outwardly from at least one of the first and second siderails, and the step member supports being coated by the coating.
 7. Theboat trailer of claim 3, further comprising fender supports on whichfenders are supported, the fender supports projecting outwardly from thefirst and second side rails, and the fender supports being coated by thecoating.
 8. The boat trailer of claim 1, wherein the first and secondside rails encapsulated by the coating have a generally rectangularcross-sectional shape.
 9. The boat trailer of claim 1, wherein the firstand second side rails encapsulated by the coating have a generallyC-shaped cross-sectional shape.
 10. The boat trailer of claim 1, whereinthe boat trailer defines a central longitudinal axis that extendsbetween the front and back ends of the frame at a location between thefirst and second side rails, wherein the first and second side railshave generally C-shaped transverse cross-sections encapsulated by thecoating, the C-shaped cross-sections having open sides that face towardthe central longitudinal axis.
 11. The boat trailer of claim 1, furthercomprising step member supports positioned adjacent to the front end ofthe frame on which a step is supported, the step member supportsprojecting outwardly from at least one of the first and second rails,and the step member supports being coated by the coating, and alsofurther comprising fender supports on which fenders are supported, thefender supports projecting outwardly from the first and second rails,and the fender supports being coated by the coating.
 12. The boattrailer of claim 1, wherein the coating has a thickness of at least0.015 inches.
 13. The boat trailer of claim 1, wherein the coating has athickness in the range of 0.015 inches to 0.035 inches.
 14. The boattrailer of claim 1, wherein the coating has a thickness of 0.025 inches.15. The boat trailer of claim 3, further comprising step member supportspositioned adjacent to the front end of the frame on which a step issupported, the step member supports projecting outwardly from at leastone of the first and second rails, and the step member supports beingcoated by the coating, and also further comprising fender supports onwhich fenders are supported, the fender supports projecting outwardlyfrom the first and second rails, and the fender supports being coated bythe coating.
 16. The boat trailer of claim 3, wherein the coating has athickness of at least 0.015 inches.
 17. The boat trailer of claim 3,wherein the coating has a thickness in the range of 0.015 inches to0.035 inches.
 18. The boat trailer of claim 3, wherein the coating has athickness of 0.025 inches.